This invention relates to a device which is propelled on the underside of an ice mass formed on a body of water.
Often it is desirable to gain access to water laying underneath expansive ice blocks. Ice fishing, popular in the winter months in colder climates when the ice is thick enough to walk on, is one example. Traditionally, ice fishing utilizes tip-ups or jigging to hold the fishing line and/or alert the sportsman to a strike. Both of these items require the drilling of a hole in the ice and suspending bait dropped down the ice hole. In the first method the bait is suspended by a line from the tip-up. With jigging, the bait is attached to a line and moved up and down by the fisherman. In both cases the area being fished is limited to the water directly beneath the ice hole.
Unfortunately, during ice fishing and other activities involving walking onto ice there is always risk that the ice may weaken causing the sportsman to fall into the water. Because of the rapid cooling effect of cold water, hypothermia with resulting death can occur very quickly. Thus, it is important that methods to extract a partially or completely submerged sportsman be immediately available. Frequently, the only help available is a fellow sportsman.
In my U.S. Pat. No. 4,642,932, I describe an underwater icewalker used to extend various activities to areas lying under ice which were previously accessible only by submarines or divers. In particular, my invention permitted an ice fisherman to extend his bait beyond the water directly beneath the ice hole.
However, I have since discovered that the design of the icewalker of my U.S. Pat. No. 4,642,932 does not allow for bi-directional movement of the icewalker, making retrieval difficult. Other problems, such as snagging on the ice underside surface resulting in the icewalker tipping over have been encountered.
Accordingly, there remains a continuing need for improved methods to extend various activities to areas lying under ice. The present invention fulfills this need, and further provides related advantages.